A system and method for encrypting transmissions between a plurality of communication nodes and a mobile station, wherein the algorithm for generating an encryption key resides within a first communications node. A second communications node requiring encryption between the node and a mobile station requests an encryption key from the first communications node through a PMAP interface interconnecting the nodes. The first node generates the encryption key and a countersign and transmits them back to the second communications node. The transmitted countersign is compared with a countersign provided by the mobile station, and if they match, transmissions from the second communications node to the mobile station are encrypted using the provided key.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A system for providing encryption of transmissions over an air interface between a mobile station and a plurality of nodes, comprising: a voice network switching node for communicating with the mobile station and a voice network, said voice network switching node including an algorithm for calculating an encryption key for encrypting transmissions between the plurality of nodes and the mobile station and a countersign in response to a random number; a packet data network switching node for communicating with the mobile station and a packet data network, said packet data network switching node requesting the encryption key for encrypting transmissions to the mobile station and a contersign from the voice network switching node and requesting the countersign from the mobile station, said request including the random number, said packet data network switching node further comparing the countersign from the voice network switching node and the countersign from the mobile station and providing encrypted communications between the mobile station and the packet data network switching node using the encryption key; and a backbone interface for interconnecting the voice network switching node and the packet data network switching node.
2. The system of claim 1, wherein the voice network switching node comprises a mobile switching center.
3. The system of claim 2, wherein the packet data network switching node comprises a packet mobile switching center.
4. The system of claim 1, wherein the backbone interface provides for communications between the voice network switching node and the packet data network switching node using a PMAP protocol.
5. A method for encrypting transmissions between a voice network node, a packet data network node and a mobile station, wherein the algorithm for generating an encryption key resides within only the voice network node, comprising the steps of: requesting, at the packet data network node, an encryption key from the voice network node and a countersign from the voice network node and the mobile station; generating the encryption key and a countersign at the voice network node responsive to the request; transmitting the generated encryption key and countersign to the packet data network node from the voice data network node; generating the countersign at the mobile station responsive to the request; transmitting the generated countersign to the packet data network node from the mobile station; comparing at the packet data network node the countersign received from the voice network node with the countersign provided by the mobile station; and encrypting transmission between the packet data network node and the mobile station using the encryption key if the countersigns match.
6. The method of claim 5, wherein the step of requesting further comprises the step of: transmitting a request to the voice network node using a PMAP protocol.
7. The method of claim 6, wherein the step of transmitting further comprises the step of: transmitting the generated encryption key and the countersign to the packet data network node from the voice network node using the PMAP protocol.
8. The method of claim 5, wherein the step of requesting further comprises the steps of: obtaining a random number; and transmitting an encryption key request to the voice network node, the encryption key request including the random number.
9. The method of claim 5 further including the step of: requesting packet data communications between the PMSC node and the mobile station.
10. The method of claim 5 further comprising the steps of: requesting the countersign from the mobile station; calculating the countersign at the mobile station; and transmitting the calculated countersign to the PMSC node.
11. A method for encrypting transmissions between MSC and PMSC nodes and a mobile station, wherein an algorithm for generating an encryption key resides within the MSC node, comprising the steps of: generating a random number by the PMSC; transmitting the random number to the MSC using a PMAP protocol; calculating the encryption key and a countersign at the MSC; transmitting the encryption key and the countersign to the PMSC using the PMAP protocol; comparing the countersign received from the MSC with a countersign provided by the mobile station to confirm a match; and encrypting transmissions between the PMSC and the mobile station using the encryption key.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 8, 1998
December 25, 2001
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